(1) Field of the Invention
The present invention relates to an eyeglass lens processing apparatus for processing a periphery of an eyeglass lens.
(2) Description of the Related Art
An eyeglass lens processing apparatus capable of forming a bevel at a periphery of an eyeglass lens, including a beveling grindstone having a beveling groove in a V-like shape constitutes the main stream. Generally, a large-sized beveling grindstone having a diameter equal to or larger than 100 mm is used in consideration of a consuming property similar to a roughening grindstone.
In recent years, according to an eyeglass frame, owing to a variety of its formation, a frame having a rim having a large warp (hereinafter, also referred to as a frame curve) has been increased. When a lens is fitted to such a rim, a lens having a large warp (hereinafter, also referred to as a lens curve) is selected. Further, a periphery of a selected lens having a steep lens curve is formed with a bevel in a path of a steep curve to match an inner groove of a rim having a steep frame curve.
However, when a bevel having a path in a steep curve is formed by a general beveling grindstone having a large diameter, a beveling groove of the beveling grindstone and the formed bevel interfere with each other to bring about an error of processing the bevel.
Further, such a problem can be dealt with by providing a small diameter beveling grindstone to the apparatus other than the general large-diameter beveling grindstone. However, the beveling grindstone is expensive, further, the beveling groove has a fixed shape, and therefore, a formable shape of the bevel is considerably limited.